Plane sex is a pain.

Is joining the mile-high club on your sex fantasy to-do list? It might not be after you hear what 26-year-old Diana has to say. On a flight home from Tennessee to New York, she and her boyfriend got “the itch” and started hooking up under a blanket—which soon led to an all-out sexcapade in the lavatory. “I went ahead to use the bathroom and didn’t actually think my boyfriend would knock seconds later,” she says. “I tried to finish up quickly and shut the commode—without flushing—and let him in. We did it standing up, doggie style. There was absolutely no room. My face was smushed against the wall, right above the commode, which still had my pee in it. It was hot—and I mean warm and stuffy—not sexy. Five minutes later, we were done, and I couldn’t wait to fly out of that bathroom.”

Why hot tubs are so not hot.

Hot, bubbling water sure does set the mood, tickling all the right places, right? Wrong. “Sex in a hot tub can cause serious health problems. Hot tubs are a breeding ground for bacteria that increase the likelihood of infection, including UTIs, yeast infections and rashes,” says Melissa L. Fox, an R.N. in Farmington Hills, Mich. “The extreme temperature and chemicals wash away much of a woman’s natural lubrication, which in turn may cause microscopic tears.” Sexy.

Say bye-bye to sex on the beach.

Turns out the drink is the sexier option. “Two words: sand fleas. You won’t know they’ve even bit you down there until hours later, when you have an itch you really can’t scratch in public,” says, Mary Jo Fay, R.N., M.S.N, and the author of Please Dear, Not Tonight: The Truth About Women and Sex. And bugs aren’t the only things that bite about having sex on the beach. Let’s not forget about sand, which can be easily introduced into the vagina, causing discomfort when friction ensues and infection if stray grains remain after lovemaking. Still not sold? Kristina, 28, of Weehawken, N.J., was caught mid-tryst. “We were doing it on the beach, and all of a sudden this voice comes over a megaphone telling us to put our clothes on because we were engaging in inappropriate behavior,” she says. That’s right, sex on the beach could lead to a night in the slammer—and there’s nothing sexy about that.

Nix getting wild in the wilderness.

“I thought it would be spontaneous and fun to lure my guy away from the group on our couples camping trip. Then I got poison ivy on my butt,” says Jaz, 28, from Los Angeles. Fay agrees: “Is a few moments of ecstasy worth days of itching and treating poison ivy, oak, sumac and nettle? No!” When you’re in the moment, you won’t be examining leaf after leaf and referring to Google Images to see what you’re about to lie on. It’s also pretty hard to run away from a bear with your panties at your ankles…just saying.

Can car sex.

Here’s why doing it in a car day or night is never ever sexy: When Krista, 37, of Virginia Beach, Va., suddenly felt frisky, she made her man pull over—in broad daylight! “A guy in a semi passed us and gave a couple of playful honks of his horn,” says Krista. “We thought nothing of it, assuming we wouldn’t see him again. Well, here’s some info about truckers: They have CB radios, and they love to talk when they’re on long, boring drives. That trucker told every long-hauler what he saw, and we got honked at and waved to by countless truckers.”

Stall before having sex in the restroom.

Veronica, 27, of Van Nuys, Calif., once persuaded a guy to join her in a cramped Porta-Potty, claiming she had to have sex no matter where. She says it was clean but followed up with an “ew” in the same sentence, so if you ask us, she’s trying to convince herself that it wasn’t too gross. Her guy sat on the bowl (you never want to see your dude sitting on the bowl), and she jumped on. If that mental image isn’t reason enough to skip this sex spot, just think about all the germs crawling around there. Ew, indeed.

Ban the boat dock.

When 36-year-old Cristal of Wylie, Texas, wanted to spice things up, she took her guy down to the docks. Was it sexy? Let’s see: waves curling in the distance, the moon aglow just overhead, the smell of salt water—OK, a boat dock does seem like a sensual place to get it on. Until you realize that it’s made of hard, rough wood. “Getting splinters in delicate places while having sex can be a literal pain in the butt,” says Carol Carrozza, vice president of marketing for LifeStyles condoms. “Not to mention, latex can be particularly susceptible to objects with sharp points like jagged wood, so always make sure the condom isn’t exposed to anything with a sharp edge, like the surface you’re doing it on.” Good idea.

And a sexy-sounding spot that really is: a playground.

Let’s just get this out of the way first: Racy playground moves are a nighttime-only activity. Now, to the fun stuff. Chrystal Bougon, sex expert and blogger at blissconnection.com, says to get your game on at a playground. “Playgrounds are like an adult jungle gym—fabulous for some slippery love on the slide or a dizzying romp on the merry-go-round and round and round,” she says. Need more convincing? Bougon reminds us of that “built-in sex swing” and how the monkey bars can double as an impromptu stripper pole.